Food product positioning system and method

ABSTRACT

A food handling system having a positioning system and method. The positioning system includes a main conveying surface, an electronic sensor, a controller and a robot. The main conveying surface is configured to move food products. The electronic sensor is configured to capture position data about one or more food products on the main conveying surface within a sensor range of the sensor. The controller is signal-connected to the electronic sensor and the robot. The controller is configured to receive data captured by the sensor and is configured to instruct the robot to move a food product to a destination position. The robot is configured to reposition one or more food products on the conveying surface according to instructions sent by the controller. The robot has a longitudinal and a lateral working range. The food product may include formed meat patties or sliced meat or cheese products.

RELATED APPLICATIONS

This application is a divisional of co-pending U.S. patent applicationSer. No. 12/606,846, filed Oct. 27, 2009, which claims the benefit ofU.S. Provisional Patent Application No. 61/108,789, filed Oct. 27, 2008,the contents of all of which are incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a system for handling food products from anapparatus that slices or forms the food products. Particularly, theinvention relates to food product positioning system for positing foodproducts on a conveyor.

BACKGROUND OF THE INVENTION

Food product machines, particularly high speed slicers, produce groupsof food products. Those groups may be stacked vertically or may beshingled. Food patty forming machines product food product includingformed meat patties. The food products may be conveyed away from thefood product machine by a main conveyor. The groups of food products maythen be supplied to packaging equipment, such as a fill and packageapparatus, in a food product stream to be packaged for shipment. Thefood products as received from the food product machine may not be in apreferred predefined position or orientation on the conveyor tofacilitate optimum or efficient downstream processing, such aspackaging.

Sliced food products may be formed from a slicer such as disclosed inU.S. Pat. Nos. 5,628,237, 5,974,925, herein incorporated by reference,and commercially available as a FX180® slicer machine. The slicer mayalso be such as disclosed in U.S. Patent Application No. 60/999,961,herein incorporated by reference, and commercially available as aPowerMax4000™ slicer available from Formax Inc. of Mokena, Ill., USA.Formed food products may be made by a patty forming machine such asdisclosed in, for example, U.S. Pat. Nos. 3,952,478; 4,054, 967;4,182,003; and 4,329,828, and PCT published applications WO 99/62344,and WO 2005/02766782 A2, herein incorporated by reference, or thosecommercialized by Formax, Inc. of Mokena, Ill., including the F26™,ULTRA26™, Maxum700®, F-19™, F-400™, or F6™ patty forming machines.

In one type of fill and package apparatus for sliced food products, aslicer delivers groups of slices or “drafts” onto a conveyor. The draftsare conveyed spaced-apart in a stream to a staging conveyor where thestream is converted to lateral rows of drafts. Such a staging conveyoris described in U.S. Pat. No. 5,810,149, herein incorporated byreference, and commercially available as the A*180 Autoloader fromFormax, Inc. of Mokena, Ill., U.S.A. Alternatively, the drafts may beplaced on the conveyor by the slicing machine in lateral rows of draftsalleviating the need of a staging conveyor. Fill and package apparatusfor sliced or formed food products are disclosed in U.S. Pat. No.7,065,936 or U.S. Pat. No. 7,328,542, which are herein incorporated byreference.

In one type of fill and package apparatus for formed food products, thepatty forming machine delivers a formed food product or a stack of foodproducts onto an output conveyor. When formed food products are providedas a stack of food products, a food product forming machine may eject anumber of food products on top of one another before the food productsare advanced by the output conveyor. Also, a paper interleaving devicesuch as disclosed in U.S. Patent Application No. 60/730,304, which ishereby incorporated by reference, and commercially available from FormaxInc., may be placed at the output of the food product forming machine tointerleave paper between each food product in a food product stack.Whether the food products lay individually or in stacks on the outputconveyor, the food products may be arranged in transverse rows.

The food product groups must be maintained within close tolerances,particularly as to weight; under-weight groups constitutes a potentialfraud on the ultimate users and overweight groups may represent anappreciable loss of revenue to the plant operator. Even with the mostsophisticated and technologically advanced controls, the slicingmachines and like food product machines that produce the groups of foodproducts may not always maintain those groups within the presettolerance limits. This is particularly true when the food productmachine first starts in operation and again whenever there is any changein operation, such as a change from one food loaf to another in theoperation of a food loaf slicer or a change of bacon slabs in a baconslicer. Moreover, even those food products that are within the presettolerance, known as “accept” groups, must be transported to a packagingstation or other utilization location.

To minimize waste, it is desirable to correct any out-of-tolerance or“reject” food product groups. A check weight conveyor, such as disclosedin U.S. Pat. Nos. 6,997,089 and 5,499,719, and U.S. Patent ApplicationSer. No. 60/729,957, and Ser. No. 11/454,143, may be used to divertrejected food products to an off-weight stream or food productcorrection stream or location. When rejected food products are taken outof the main food product stream a food product vacancy is created in thefood product stream.

The present inventors recognize it is advantageous to re-orientate orreposition food products received from a food product machine on aconveyor. The present inventors recognize it would be desirable toprovide a device capable of precisely orientating or positioning one ormore food products on a moving conveyor. The present inventors recognizethat it would be desirable to provide a device capable of preciselyorientating or positioning food products on a moving conveyor tofacilitate efficient and optimum or efficient downstream processing,such as packaging.

SUMMARY OF THE INVENTION

The invention includes a food handling system having a positioningsystem. The positioning system includes a main conveying surface, anelectronic sensor, a controller and a robot. The main conveying surfaceis configured to move food products. The electronic sensor is configuredto capture position data about one or more food products on the mainconveying surface within a sensor range of the sensor. The controller issignal-connected to the electronic sensor and the robot. The controlleris configured to receive data captured by the sensor and is configuredto instruct the robot to move a food product to a destination position.The robot is configured to reposition one or more food products on theconveying surface according to instructions sent by the controller.

In one embodiment, the robot has a longitudinal working range forpositioning a one or more food products to a destination position eitherupstream or downstream from an original position of the food productwith respect to a conveying direction of the conveying surface.

In one embodiment, the robot has a lateral working range for positioningone or more food products to a destination position transverse from anoriginal position of the food product in relation to a conveyingdirection of the conveying surface.

In one embodiment, the sensor captures an orientation of one or morefood products on the conveying surface within the sensor range.

In one embodiment, the controller has instruction for determiningwhether a food product is in a mis-orientated position on the conveyingsurface by comparing a measured orientation with a predefinedorientation or a predefined orientation range. The controller hasinstructions for directing the robot to move a particular food productfrom the misorientated position to a corrected orientation. The robothas a rotatable ripper for rotating an orientation of one or more foodproducts about at least one axis of rotation.

In one embodiment, the controller has instruction for determiningwhether a food product is in a misaligned position on the conveyingsurface. The controller has instructions for directing the robot to movea particular food product from the misaligned position to an alignedposition.

In one embodiment, each food product has a transverse position and alongitudinal position on the conveying surface. The sensor is capable ofgenerating a signal representing a captured position including thetransverse and the longitudinal position of one or more food products onthe conveying surface within the sensor range. The controller hasposition determining instructions configured to compare the capturedposition with a predefined position to determine whether the product ismis-positioned; and the controller is configured to send corrected foodproduct movement instructions to the robot to move a mis-positioned foodproduct to a corrected food product position.

In one embodiment, the controller has a datastore having at least onepredefined transverse centerline value representing a transverseposition on which selected food products are to be aligned to form atransverse row on the conveying surface. The controller has a misalignedfood product calculating instruction for determine whether a measuredfood product position value received from the sensor is outside of thetransverse centerline value. The controller is configured to instructthe robot to move one or more misaligned food products into an alignmentposition on the transverse centerline.

In one embodiment, the controller has a datastore having at least onepredefined longitudinal centerline value representing a longitudinalposition on which the food products are to be aligned to form atransverse row on the conveying surface. The controller has a misalignedfood product calculating instruction for determine whether a measuredfood product position value received from the sensor is outside of thelongitudinal centerline value. The controller is configured to instructthe robot to move misaligned food products into an alignment position onthe longitudinal centerline.

In one embodiment, the robot is configured to re-positioning foodproducts on the conveying surface while the conveying surface is moving.The robot may also be configured to re-orientate food products while theconveying surface is moving.

In one embodiment, the robot has a gripper for holding the food product.The gripper has at least two gripping arms. The gripper has an openposition for releasing a food product, and a closed position for holdingand transporting a food product. The gripping arms may have lowersupports for supporting the bottom of a food product when the grippersare in a closed position.

In one embodiment, the system includes a rotatable slicing blade, aconveying assembly, and a support for holding a loaf in a cutting pathof the rotatable slicing blade, the slicing blade arranged to rotate inthe cutting path to slice drafts from the loaf, the drafts being pluralslices formed in a pile on the conveying assembly and the piles aretransported onto the main conveyor.

In one embodiment, the system includes a patty-forming machine, thepatty-forming machine having a machine frame, a mold plate having atleast one cavity and mounted to reciprocate in a longitudinal directionwith respect to the frame to position the cavity between a fill positionand patty knock out position, a food product delivery channel fordelivering food product into the cavity, the food product deliverychannel mounted stationary with respect to the frame and having a fillopening into the cavity when the mold plate is in the fill position, oneor more knockout plungers for expelling the formed food product from themold plate onto an output conveyor when the mold plate is in theknockout position.

Numerous other advantages and features of the invention will becomereadily apparent from the following detailed description of theinvention and the embodiments thereof, from the claims, and from theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view of a food product forming and packagingline that incorporates the invention;

FIG. 1A is an enlarged side view, taken from FIG. 1, of an outputconveyor including a weigh conveyor and a classifying conveyor;

FIG. 1B is an end view of an optical grading system and the classifyingconveyor;

FIG. 2 is a top view taken from FIG. 1;

FIG. 3 is a side view of a packing station;

FIG. 4 is a side view of the packing station with the shuttle robot notcompletely shown;

FIG. 5A is a side view of a gripper;

FIG. 5B is a second side view of the gripper and a main conveyor;

FIG. 5C is a top view of the gripper;

FIG. 6 is an enlarged top view taken from FIG. 2 of a main conveyor, aworking area of an alignment robot, an off-weight conveyor, a correctionstation, a parking station, and a fill station;

FIG. 7 is an enlarged top view taken from FIG. 2 of the main conveyor,the working area of the alignment robot, the off-weight conveyor, thecorrection station, the parking station, and the fill station showingfood products shaped different from those shown in FIG. 6; and

FIG. 8 is a side view of the alignment robot and the main conveyor.

DETAILED DESCRIPTION

While this invention is susceptible of embodiment in many differentforms, there are shown in the drawing and will be described herein indetail specific embodiments thereof with the understanding that thepresent disclosure is to be considered as an exemplification of theprinciples of the invention and is not intended to limit the inventionto the specific embodiments illustrated. This application claims thebenefit of U.S. provisional patent application Ser. No. 61/108,789 filedon Oct. 27, 2008, which is hereby incorporated by reference.

System Overview

As shown in FIGS. 1 and 2, a system according to the invention includesa slicing machine 20 which cuts slices from one or more loaves anddeposits the slices on an output conveyor assembly 30, forming shingledor stacked drafts, or food products. The drafts can be piles, bunches orgroups of thin sliced product. The slicing machine 20 can be of a typeas described in U.S. Pat. Nos. 5,649,463; 5,704,265; and 5,974,925; aswell as patent publications EP0713753 and WO99/08844, hereinincorporated by reference. The slicing machine 20 can also be a FORMAXFX180 machine, commercially available from Formax, Inc. of Mokena, Ill.,U.S.A.

In one embodiment shown in FIG. 1A, the output conveyor assembly 30includes a check weight conveyor 32, such as disclosed in U.S. Pat. Nos.6,997,089 and 5,499,719, and U.S. Patent Application Ser. No.60/729,957, and Ser. No. 11/454,143, wherein unacceptable drafts can berejected and diverted. In another embodiment as shown in FIG. 1B, theconveyor assembly 30 includes an optical grading system 70, such asdisclosed in U.S. Pat. No. 6,997,089, which is herein incorporated byreference. In another embodiment, the conveyor assembly 30 comprises aclassifying conveyor 42 as shown in FIG. 1A. The weighing conveyor 32,and the optical grading system 70, and the classifying conveyor 42 arelocated upstream of a main conveyor 120 and an alignment robot 200.

An off-weight conveyor 220 is at least partially adjacent to the mainconveyor 120 as shown in FIG. 2. The off-weight conveyor 220 connects toa weight correction station 228. The weight correction station 228connects to a parking station 230.

The system comprises an alignment and orientation camera or sensor 210that has a sensor range area 212 focused on an area upstream and/orwithin a working diameter or area 209 of an alignment robot 200. Thealignment robot is located above the main conveyor 120. A shuttle robot100 is located above or adjacent to a downstream end portion of the mainconveyor 120 and a fill station 110 and has a shuttle working diameteror area 410. A shuttle camera or sensor 420 having at least one sensorrange 430 focused on a downstream end of the main conveyor. A packagingmachine 60, such as a Multivac R530, available from Multivac, Inc. ofKansas City, Mo., U.S.A., is located below the main conveyor 120.

In one embodiment, the system comprises a staging conveyor locatedbetween the machine 20 and the robot 200. Drafts are conveyedspaced-apart in a stream to a staging conveyor where the stream isconverted to lateral rows of drafts. Such a staging conveyor isdescribed in U.S. Pat. No. 5,810,149 and is commercially available asthe A*180 Autoloader from Formax, Inc. of Mokena, Ill., U.S.A.Alternatively, the drafts may be placed on the conveyor by the slicingmachine in lateral rows of drafts alleviating the need of a stagingconveyor.

At the fill station 110 of the packing machine 60, the shuttle robot 100delivers food products from an upstream main conveyor 120 intocontainers 131. The containers 131 may be formed in a group of rows ofpockets 131 formed in a lower web 133 of film by the packaging machine60. Downstream of the fill station 110, in the direction D, is a sealingstation 170. The containers or pockets 131 that are filled with foodproduct, are sealed by an upper web of film in the sealing station 170.

The machine 20 may also be a food product forming machine such asdisclosed in, for example, U.S. Pat. Nos. 3,952,478; 4,054, 967;4,182,003; and 4,329,828, and PCT published applications WO 99/62344,and WO 2005/02766782 A2. The food product forming machine delivers aformed food product or a stack of food products onto an output conveyor30. Therefore the shingled or stacked drafts 150 may also be formed foodproducts 150, both of which may be referred to as food products 150. Theformed food product 150 a may be such as those shown in FIG. 6 or may beof another formed shape. Whether the food products 150 lay individuallyor in stacks on the conveyor 30, the food products may be arranged inrows transverse to the conveying direction.

A controller 180, such as an electronic circuit, a programmable logiccontroller (PLC), a microprocessor, a CPU, computer, or other controldevice, is signal-connected to the shuttle robot 100, the alignmentrobot, the packing machine 60, the machine 20, a sensor or camera 210,the sealing station 170, and at least one of a vacancy detector 214 aand vacancy detector 214 b.

The controller may comprise a datastore being a electronic or computerhardware or software memory or harddrive containing predefined values,such as food product orientation values, food product longitudinalposition values, food product lateral position values, transversecenterline value representing a transverse position on which selectedfood products are to be aligned, longitudinal centerline valuesrepresenting a longitudinal position on which the food products are tobe aligned, food product position values. These values may be userdefined or predefined for various types of food products. The controlleran instruction storage area for storing preprogrammed, user defined, orother instructions that the controller uses to process and/analyze thedata according to machine operation programming.

Off-Weight Conveyor

FIGS. 2, 6, and 7 shows the off-weight conveyor 220 comprises anadjacent longitudinal portion 222, a downstream end portion 224, and anupstream end portion 226. The off weight conveyor 200 is connected to acorrection station 228, which may be a weight correction station. Theweight correction station 229 is connected to a food product parkingstation 230.

In one embodiment, the longitudinal portion 222 is adjacent and parallelto the main conveyor 120. The weight correction station 228 and theparking station 230 are adjacent and parallel to the main conveyor 120on a side of the conveyor 120 opposite the longitudinal portion 222. Theparking station is downstream 230 from the weight correction station228. The correction station 228 is connected to the longitudinal portion222 by the upstream end portion 226. The upstream end portion 226 curvesfrom its connection point with the longitudinal portion to be positionedperpendicularly to the conveying direction. The upstream end portionextends under the main conveyor 120 and curves to connect with thecorrection station 228. Thus, the upstream end portion 226 forms a Ushape as it extends under the main conveyor. In another embodiment,portions of the off-weight conveyor 220 may not curve to connect to oneanother, but rather may connect at an angle including a right angle. Inanother embodiment, the upstream end portion 226 may cross the mainconveyor 120 non-perpendicularly. Moreover, the upstream end portion maycross above the main conveyor 120.

The downstream end portion 240 is located between a pickup location 140at a downstream end of the main conveyor 120 and the fill station 110(FIG. 1). The downstream end portion connects to the longitudinalportion 222 and curves from its connection point with the longitudinalportion to be positioned perpendicularly with the conveying direction.The downstream end portion 224 is vertically positioned below aconveying surface of the main conveyor 120 and above the filling station110, as best shown in FIG. 4. In another embodiment, the downstream endportion 224 is vertically positioned co-planer with the conveyingsurface. In another embodiment, the downstream end portion 224 may bepositioned non-perpendicularly with respect to the conveying direction.

Alignment Robot

FIG. 1 shows an alignment robot 200 downstream from the food productmachine 20 and the output conveyor 30. In one embodiment, the camera orsensor 210 is upstream of the alignment robot 200. The sensor range area212 of the sensor or camera 210 is focused on an area upstream and orwithin the working diameter or area 209 of an alignment robot 200. Thecamera 210 and the alignment robot are signal-connected to a controller180. In one embodiment, the alignment robot 200 may be a picker robot ora delta robot, such as disclosed in U.S. Pat. Nos. 7,188,544, 6,577,093,and U.S. Patent Application No. 2006/0182602, each patent and patentapplication being herein incorporated by reference. A device of thebasic delta robot concept is disclosed in U.S. Pat. No. 4,976,582 and isincorporated by reference. In another embodiment, the alignment robot200 may be a four arm picker/delta robot such as the Quattro™ 650 robotmanufactured by Adept Technologies Inc. having its corporateheadquarters located in Livermore, Calif. in 2008.

As shown in FIG. 8, the alignment robot 200 is located above the mainconveyor 120 and the off weight conveyor 220. In one embodiment therobot has a base 205. Four motors are mounted in the base 205 and movefour first arms 201, 202, 203, 204. A pair of pull rods are pivotablyattached to each first arm. Pull rods 202 a and 202 b connect to firstarm 202; pull rods 204 a and 204 b connect to first arm 204; pull rods201 a and 201 b (not shown) connect to first arm 201; pull rods 203 a(not shown) and 203 b connect to first arm 203. Each pair of pull rodspivotably connect to a movable plate 206. The first arms, the connectorarms and the movable plate comprise an arm system 208 of the robot. Agripper 160, such the one shown in FIG. 5, may be attached to themovable plate 206 for gripping and moving a food product.

The robot can be placed in a frame construction (not shown) above theconveyor 120. In one embodiment, the arm system 208 is able to rotatewith at least three degrees of freedom in Cartesian X, Y and Zdirections.

In one embodiment, the robot 200 has the working area or diameter 209(FIGS. 2, 6, 7) of 1300 mm along the Cartesian x and y axes. The robot200 has a working height, in the vertical direction or the Cartesian zaxis, in the range of 250 mm to 500 mm. The robot has the ability torotate the movable plate 206 one hundred and eighty degrees in onedirection and one hundred and eighty degrees in the opposite direction.The robot has a maximum linear movement speed of 10 meters per secondand a rate of acceleration of 150 meters per second squared.

Alignment and Orientation Sensor

In one embodiment, as shown in FIGS. 1, and 8, the alignment andorientation sensor or camera 210 is located upstream of the alignmentrobot 200 and downstream of the output conveyor assembly 30. Regardlessof where the camera 210 is located, the sensor range area 212 of thecamera 210 is focused on an area upstream and/or within the workingdiameter or area 209 of an alignment robot 200. The camera 210 issignal-connected to the controller 180. The camera 210 is mounted on asupport structure (not shown) above or adjacent to the conveyor 120.

The camera 210 and controller 180 comprises a vision system. In oneembodiment, the camera 210 is that described in U.S. Pat. No. 6,997,089,which is herein incorporated by reference. The vision system iscontrolled by the controller 180. The controller 180 may be anelectronic circuit, a programmable logic controller (PLC), amicroprocessor, a CPU or other control device. In one embodiment, thecamera 210 and the controller 180 may comprise a single unit.

In one embodiment, the camera 210 is an ELECTRIM EDC-1000N black andwhite 640×480 pixel digital camera 34 with a 4.8 mm lens. The controller180 includes a digital frame grabber PC-104 printed circuit board, and aPC-104 CPU main processor board. In this embodiment, the vision systemmay also include a light source to provide illumination of the foodproduct 150.

Alignment Robot Operation

In operation, the camera 210 scans each food product 150 or each row offood products 151 as they pass under the camera 210 on the conveyor 120and within the sensor range area 212. The camera sends data tocontroller 180 concerning various characteristics of the food product150, including food product position, orientation, and alignment on theconveyor 120. The controller 180 has instructions for analyzing thedata.

When the controller executes instructions to determine a particular foodproduct or stack of food products is not in a predefined preferredorientation, the controller 180 will send re-orientation instructions tothe robot 200. When misorientated food product 150 is within the workingdiameter 209, the robot will move the food product to the preferredposition and orientation according to the re-orientation instructionsfrom the controller 180.

As shown in FIG. 6, food product 150 a is misorientated within foodproduct row 151 a. The controller 180 receives position, orientation,and alignment data or information about food product 150 a from thecamera 210. While or before the food product reaches the workingdiameter 209, the controller executes analyzing instructions comparinglocation and orientation values received from the camera to predefinedlocation and orientation values. If a particular food product isdetermined by the controller to be mis-positioned or mis-orientated, thecontroller sends instructions to the robot to move food product 150 ainto a predefined proper or preferred orientation and/or orientation.When food product 150 a reaches the working diameter 209 of the robot200, the robot carries out the instruction and moves and re-orientatesthe food product so that is it in proper orientation and alignment asshown by food products 150 b and 150 c. Food products 150 b and 150 crepresent food product 150 a after it is reorientated by the robot andconveyed downstream at various points downstream.

Referring to FIG. 7, the food products of row 151 c are misalignedlongitudinally and transversely with the conveying direction and theyare also misorientated. The camera 210 will have obtained position dataabout each food product at or upstream of the working diameter 209 ofthe robot 200. Assuming food product 150 e fits the predefined properposition and orientation, the controller will instruct the robot 200 tomove food product 150 d along the y axis toward the edge of the conveyor180, rotating it slightly to be square with a plane defined by theconveyor edge. The controller will instruct the robot 200 to move foodproduct 150 f downstream in the X direction relative to the row 151 c.The controller will instruct the robot 200 to re-orientate food product150 g to be square with the plane defined by the conveyor 120 edge. Therobot will carry out these instructions making the appropriate movementof the food products while the food products are within the workingdiameter 209 so food product row 151 c is aligned and orientated asshown by food product row 151 h after the robot carries out theinstructions from the controller 180. The controller is able to instructthe robot 200, and the robot is able to carry out any repositioninginstructions while the conveyor 120 is in continuous motion. Todetermine what food products are to be within a particular row, thecontroller will analyze data from the sensor comprising a row width forfood products positioned therein and defining the scope of food productsto be considered as within a given row. The row width is a predefinedarea within which food products are to be aligned on a predefined rowalignment within a predefined row.

The controller 180 may be programmed to provide orientation or alignmentinstructions for food products or food product rows according to anyuser defined or pre-defined orientation or alignment on the conveyor120.

In one embodiment, the camera 210 will detect when a stack of foodproducts 150 is not properly stacked or aligned in the verticaldirection along the Cartesian Z axis (FIG. 1). The controller 180 willinstruct the robot to correct the vertical mis-alignment, for example,by straightening the stack with the arms 161 (FIG. 5A) of the gripper160, when the robot has the gripper 160, such as shown in FIG. 5A,attached to the movable plate 206. The robot may also align by movingindividual food product of a food product stack to bring the foodproduct stack into the preferred vertical alignment.

Off-Weight Conveyor Operation—Robot Uncorrectable Food Products

In one embodiment, the camera 210 will detect and the controller willdetermine when a food product/food product stack is not correctable bythe alignment robot 200. An uncorrectable food product is when a foodproduct 150 or a stack of food products is misaligned or misorientatedto the extent that the robot 200 cannot bring the food product or thestack of food products into the predefined preferred alignment orpredefined preferred orientation. When a food product is uncorrectable,the controller will not instruct the robot 200 to correct the foodproduct. In one embodiment, the uncorrectable food product will travelto a downstream end 122 (FIGS. 6, 7) of the main conveyor 120. Thecontroller will not instruct the shuttle robot 100 to pick up theuncorrectable food product or stack or will affirmatively instruct therobot not to pick up the uncorrectable food product. The uncorrectablefood product or stack will fall onto the downstream end 224 of theoff-weight conveyor 220. Alternatively, in another embodiment, thecontroller may instruct the shuttle robot 100 to pick up theuncorrectable food product and place it on the downstream end 224 of theoff-weight conveyor 220.

The off-weight conveyor 220 will convey the robot-uncorrectable foodproduct to the off-weight station 228 where it will be corrected by ahuman 229 or another robot, or it will be discarded or recycled. At theoff-weight station 228, the food product may be added or subtracted tobring the food product or food product stack to a predefined weight or apredefined weight range. The food product may also be restacked, alignedor orientated at the off-weight station 228. The corrected food productis moved to the parking station 230.

Off-Weight Conveyor—Weighing and Classifying Conveyors

As shown in detail in FIG. 1A, in one embodiment, the output conveyor 30includes a classifier conveyor system 40, such as described in U.S. Pat.No. 5,499,719, which is herein incorporated by reference. A classifierconveyor 42 is selectively pivoted by an actuator 44, by signal from thecontroller 180, to deliver food products alternately to the off-weightconveyor 220 or the main conveyor 120. The actuator 44 can be apneumatic cylinder with an extendable/retractable rod 46 connected tothe classifier conveyor 42.

The weighing conveyor 32 is located upstream of the classifying conveyor42. The weighing conveyor 32 signals to the controller 180 the weight ofeach food product or food product stack that passes over the weighingconveyor 32. When the controller 180 determines that a particular foodproduct or food product stack is not within a pre-defined weight rangeor a specific pre-defined weight, the controller 180 signals to theclassifying conveyor 42 to lower the classifying conveyor to a rejectposition 42 b. In the reject position 42 b, the classifying conveyorconnects to the upstream end portion 226 of the off-weight conveyor 220.The off-weight food product is then carried by the off-weight conveyor200 to the weight correction station 228. When the classifying conveyor42 is in a raised accept position 42 a, it connects with the mainconveyor 120.

The off-weight conveyor 220 will convey the off-weight food product tothe off-weight station 228 where it will be corrected by a human 229 oranother robot; it will be discarded or recycled. At the off-weightstation 228, food product slices may be added or subtracted to bring thefood product or food product stack to a predefined weight or apredefined weight range. The food product may also be restacked, alignedor orientated at the off-weight station 228. The corrected food productis then moved to the parking station 230.

Optical Grading System and Classifying Conveyor

In one embodiment, the output conveyor 30 comprises an optical gradingsystem 70, such as disclosed in U.S. Pat. No. 6,997,089, which isincorporated by reference. FIG. 1B illustrates the optical gradingsystem 70 which captures the image of the slice passing on the weighingconveyor 32. When the weighing conveyor 32 senses the slice to be viewedon the scale, the controller 180 triggers the system 70 to capture theslice image. The system 70 will capture an image of the top of the sliceon top of the stack 150 or, in the case of a single slice, the top ofthe slice. The optical grading camera 34 captures the slice image withinan image field of vision 49 pixel-by-pixel. The shutter speed of thecamera is fast enough to capture the image while the slice or stack isin motion. The image is then retrieved from the digital frame grabberprinted circuit board into the memory of the system 70 or of thecontroller 180.

Software can then perform various analyses on the digital image data.The software may be contained in the system 70, or in the CPU 12, or inthe controller 180. The slice perimeter or boundary dimensions aredetermined due to the brightness or color contrast between the slice andthe weigh scale belting on which the slice is transferred. A grayscaleanalysis, pixel-by-pixel, can be undertaken by the software, whereinblack is 0 and white is 255. An experimentally determined grayscalecutoff point between fat pixels (light) and lean pixels (dark) can beused to characterize each pixel as being fat or lean. The ratio of lightpixels (fat) to dark pixels (lean) within the slice boundary is thencalculated, as representative of a fat-to-lean ratio. Additionally,local areas constituting “flaws” in the slice can be quantified in size,by calculating and summing adjacent non-lean pixels, and then comparedto a flaw tolerance or limit. A flaw can be a fat deposit, a gland,muscle or bone piece, a void, or other undesirable bit.

Alternatively, the calculations and routines utilized to capture andevaluate slice image data can be as described in U.S. Pat. Nos.4,136,504; 4,226,540 and/or 4,413,279, all herein incorporated byreference. The mathematical analysis of pixel data can be as describedin U.S. Pat. No. 5,267,168, herein incorporated by reference.

The data is calculated and compared to predetermined standards orcustomer programmable standards regarding overall fat content and flawsize and/or quantity limits.

A calculation is made to determine whether the slice is to be classifiedas a “pass”, that is, being below stringent fat content or flaw limits,or “reject”, that is being above acceptable fat content or flaw limits,or “grade-off”, that is being below acceptable fat content or flawlimits but above stringent fat content or flaw limits.

Based on the calculated parameters and the comparison to thepre-selected tolerances, the slice is determined to be a grade reject ifthe fat-to-lean ratio is greater than the allowable tolerance, or if theslice includes a flaw, or a pre-selected number of flaws, greater insize, individually and/or in the aggregate, than an allowable tolerance.These tolerances can be adjustable and determined by the user, typicallyas a plant standard.

Advantageously, in the production of straight stacks or shingled stacksof sliced product, each slice need not the scanned, rather, the top ofeach stack can be scanned to determine a fat-to-lean ratio, and thepresence of flaws, after the stack has been cut and stacked from theloaf. The condition of the top slice, being cut from the loaf in theclose vicinity of the remaining slices in the stack, is an accuraterepresentation of the condition of all the slices in the stack.

When grading stacks of slices, the top slice of one stack is almost anexact representation of the bottom slice of the following stack. It maybe advantageous to remember this image of the top slice of a stack and“flag” it as also representing the bottom of the next stack to passbelow the camera. Combined with the next following image, the actual topof the stack, it can be accurately estimated, by evaluating the bottomand top slices of the stack, whether the entire stack meets the qualitycriteria. According to this procedure, it is not necessary to image eachand every slice in the stack or draft to accurately characterize thequality of the stack.

Thus, the stack can then be characterized as a grade reject, grade offor acceptable stack based on the characteristics of one slice of thestack or based on the characteristics of the top and bottom slices ofthe stack.

If the slice or stack of slices is determined to be a grade reject, theclassifier conveyor 42 will be pivoted by the actuator 44, by signalfrom the controller 180 to put the classifier conveyor in a rejectposition 42 b. The reject position will direct the slice or stack ofslices onto the off-weight conveyor 220. All out-of-weight toleranceslices or groups of slices, regardless of their visual acceptance, canbe placed on the off-weight conveyor 220. Products placed on theoff-weight conveyor are moved to the correction station 228, where theymay be corrected by weight, orientation, or position, or they may beremoved from the station 228 for disposal or recycling. If the operator229 or other machine of the correction station 228 corrects the foodproduct then is it optionally moved to the parking station 230.

Vacancy Filling

In one embodiment, the system has a vacancy reduction device or systemthat includes the alignment robot 200 also serving as a vacancy fillingrobot. When the classifier conveyor 42 diverts a food product to theoff-weight conveyor 230 a vacancy is created in the food product streamon the conveyor 120. An example vacancy is shown in food product row 151c in FIGS. 6 and 7. The camera or vacancy detector 210 will signal tothe controller 180 that a vacancy exists in a particular location on theconveyor. Such a vacancy is shown by the absence of at least one foodproduct as shown in food product row 151 c in FIG. 6 and food productrow 151 d in FIG. 7. A parking station sensor or food product detector214 a will signal to the controller when a food product is parked at theparking station 230. The vacancy detector 214 a, as shown in FIG. 7, maybe located adjacent to the parking station 230 or underneath (not shown)the parking station surface. Alternatively, the vacancy detector may bea sensor or camera 214 b (FIG. 1), such as the type of camera 210described above, mounted to focus the sensor range area 214 c on theparking station. In one embodiment, the parking station sensor sends asignal to the controller 180 indicating the number of food products orfood product stacks parked at the parking station 230.

The controller will instruct the robot to take a food product from aposition on the parking station to fill a vacancy, if there is a foodproduct available at the parking station when the vacancy is in theworking diameter 209 of the robot. If the product was removed from theparking station the parking station will advance another available foodproduct to fill the vacancy created by removal of the food product thatfilled the vacancy on the main conveyor 120. In one aspect of theembodiment, if the food product was parked in the first position 231then a conveying surface of the parking station will advance the nextfood product to the first position in the parking station. If there areno products in the parking station, the parking station conveyingsurface may stop advancing while the entire parking station is empty.

The controller is able to fill any vacancy in the food product stream,regardless of how it was created as long as it was created before thevacancy area advances out of the sensor area range 212 of the conveyor120.

Shuttle Sensor

In one embodiment, as shown in FIGS. 1, and 8, the shuttle sensor orcamera 420 is at the end of the main conveyor. Regardless of where thecamera 420 is located, the shuttle sensor 420 has at least one sensorrange 430, as shown in FIG. 7. The sensor range 430 comprises an endportion of the main conveyor. The sensor range 430 may include the widthof the main conveyor 120. In another embodiment, the sensor 420 has asecond sensor range 434 that comprises at least a portion 432 of thepacking station 110. The second sensor range 434 may encompass theshuttle working area 410. The sensor 420 detects food products, such asthose shown in food product row 151 h in FIG. 7. The camera 420 ismounted on a support structure (not shown) above or adjacent to thedownstream end 224 of the main conveyor 120.

The camera 410 and controller 180 comprises a second vision system. Thevision system of the camera 210 and the controller 180 may comprise thesecond vision system. In one embodiment, the camera 410 is thatdescribed in U.S. Pat. No. 6,997,089, which is herein incorporated byreference. The vision system is controlled by the controller 180. Thecontroller 180 may be an electronic circuit, a programmable logiccontroller (PLC), a microprocessor, a CPU or other control device. Inone embodiment, the camera 420 and the controller 180 may comprise asingle unit.

In one embodiment, the camera 420 is an ELECTRIM EDC-1000N black andwhite 640×480 pixel digital camera 34 with a 4.8 mm lens. The controller180 includes a digital frame grabber PC-104 printed circuit board, and aPC-104 CPU main processor board. In this embodiment, the vision systemmay also include a light source to provide illumination of the foodproduct 150.

Shuttle Robot

FIGS. 3 and 4 illustrate the shuttle robot 100 of the system. The mainor upstream conveyor 120 delivers food products 150 to the packingstation 110. The conveyor 120 may operate in a state of continuousmotion. The food products 150 may be delivered in rows 151 where thenumber of food products 150 in the rows 151 correspond to the number ofpockets or containers 131 in a row of containers 132.

The shuttle robot 100 may be suspended above or located adjacent to thefilling station 110 by a structure (not shown), so that the robotgripper 160 operates at least over the filling station and a downstreamportion of the main conveyor 120. The filling station 110 is adjacent tothe main conveyor 120. The shuttle robot has a range of motion coveringCartesian X, Y and Z directions such that the robot may movetransversely and longitudinally with respect to the conveying directionand also vertically. In one embodiment, the shuttle robot operates inthe shuttle working area 410. The shuttle robot comprises a gripper 160at a bottom of the shuttle robot 100.

In one embodiment, the shuttle robot 100 is a six-axis robot having sixdegrees of freedom, such as disclosed in U.S. Pat. No. 5,901,613, whichis incorporated by reference. A device of the basic six-axis robotconcept is disclosed in U.S. Pat. No. 4,773,813, which is incorporatedby reference. In another embodiment, the shuttle robot 100 may be asix-axis robot such as one of the Viper™ s650, s850, s1300, or s1700robots manufactured by Adept Technologies Inc. having its corporateheadquarters located in Livermore, Calif. in 2008. In anotherembodiment, the shuttle robot may be another type of robot having aworking range in the Cartesian X, Y and Z directions.

In one embodiment, the robot 100 has a maximum payload in the range of 5kg to 20 kg, a reach in the range of 653 mm to 1717 mm, and arepeatability rating in the range of plus or minus 0.020 mm to plus orminus 0.070 mm. In one embodiment, the robot has a joint range of motionfor each joint as follows: joint 1±180°, joint 2−200°, +65°, joint3+35°, +190°, joint 4±200°, joint 5±140°, joint 6±360°.

As shown in detail in FIGS. 5A, 5B, and 5C, the gripper 160 has aplurality of first arms 161 a-f, and a corresponding plurality ofoppositely facing second arms 162 a-f. The first arms are connectedtogether along or formed into a horizontal arm connection shaft 301.Similarly the second arms 162 a-f are connected together along or formedinto a horizontal arm connection shaft (not shown). The arms movebetween an open position 165 b and a closed or holding position 165 a.Each arm may have a lower support 169 a-f, 167 a-f for supporting abottom of a food product. Each arm is connected at a pivot point 168 toa horizontal arm 168 a. The pivot point may lie on the horizontal armconnection shaft. Each horizontal arm is connected to a position plate166. The position plate 166 moves vertically by a pin 163 between araised position 166 a and a lowered position 166 b by a solenoid 160 aoperatively connected to the pin 163. The vertical movement of theposition plate 166 causes each arm 161 to pivot about the pivot point168. The arms 161 are in the closed position 165 a when the positionplate 166 is in the raised position 166 a, and the arms 161 are in anopen position 166 b when the position plate is in a lowered position 166b.

In one embodiment, the gripper 160 is connected to a cross plate 340 bya plurality of bolts 344 (not shown in FIG. 5A). The cross plate 340 iscapable of supporting more than one gripper, such as gripper 310.Gripper 310 is constructed and operates in the same manner as gripper160. The cross plate connects to the shuttle robot 100 at a connectionlocation 342 with a plurality of bolts 344, 346.

When the containers are pockets 131 formed from a web 133, the packagingmachine 60 has a dwell period. At the dwell period, the packagingmachine 60 stops the motion of the lower web 133. During the dwellperiod, the packaging machine 60 forms another group of empty pockets131 upstream from the packing station 110 at a container-forming station190. The container forming station 190 is shown schematically in FIG. 4.After the dwell time period is over, the lower web of film 133 isadvanced and new food products are deposited into new containers 131 asor after the lower web 133 advances to a new dwell position.

The shuttle robot 100 has at least one pickup location 140 at an end ofthe main conveyor 120 and at least one deposit position located 144above a container 131 in the filling station 100. The shuttle robot 100may have a plurality of deposit positions located above a plurality ofcontainers 131 a in the filling station 100. The filling station 100 mayhold any number of containers for filling. FIG. 4 shows a fillingstation having four containers 131 or four rows of containers.

During the dwell period, the robot 100 moves between the pickupposition(s) and the deposit positions to move food products from themain conveyor 120 to the containers 131, 131 a.

The shuttle sensor 420 detects food products on a downstream end of themain conveyor within the sensor range 430 or second sensor range 434.The shuttle sensor sends information to the controller regarding thelocation of food products within the sensor range. The controllerdetermines whether and at what point the food products within the sensorrange should be picked up and moved to the packaging station or the offweight conveyor by the shuttle robot. The controller instructs the robotto pickup one or more food products from the main conveyor at a locationbased on the location information received from the shuttle sensor. Inone embodiment, the sensor detects which containers 131 in the packagingstation are filled with food product and which are not filled with foodproduct and sends that packaging fill information to the controller. Thecontroller may instruct the robot to move food products from the mainconveyor to the empty or incompletely filled containers in the packagingstation based on the packaging fill information from the sensor.

As shown in FIG. 4, during each pass between a particular pickuplocation and a drop or deposit location, the gripper 160 of the shuttlerobot 100 grips a food product or stack of food products at the pickuplocation 140 on the main conveyor 120. The shuttle robot may approachthe pickup location 140 in an open position as shown at 141. The shuttlerobot 100 surrounds the food product 150 a with the gripper 160 at thepickup location and moves the arms 161 of the gripper to a closedposition. The conveyor 120 may be in continuous movement during thistime such that the pickup location 140 and the shuttle robot 100 are incontinuous motion tracking the location of the food product 150 a.

The shuttle robot then moves the food product continuously orintermittently through a plurality of intermediate locations 143 to aparticular deposit location 144 located above a container 131. Thecontainer 131 may be empty or may be incomplete. When the shuttle robotis in deposit location 144 with a gripped food product, the gripper 160will move to an open position releasing the food product to fall intothe container 131.

In one embodiment, as shown in FIG. 5B, the main conveyor 120 is a stripor o-ring belt conveyor. Such a strip conveyor has a conveying surfacehaving multiple belts or strips 330, 332, 334, 336 with gaps 331, 333,335 provided between the belts. The belts are driven to rotate by adrive shaft 321 and operate around an idler shaft (not shown) oppositethe drive shaft. The gaps between the belts of the strip conveyor aresuch that the food products 151, 151 a being conveyed do not fallbetween the gaps. In one embodiment, the strip conveyor is in continuousmovement as the gripper approaches one or more target food products onthe strip conveyor. The gripper is in or is moved to an open position.The gripper tracks the movement of the food product(s) on the conveyoras the gripper lowers around the food product(s). The shuttle robotlowers the lower supports 169 a-f, 167 a-f of the arms 161 a-f, 162 a-fof the gripper 160 into the gaps of the strip conveyer below theconveying surface. The arms of the gripper are then closed bringing thelower supports 169 a-f, 167 a-f under the food products 151, 151 a. Theshuttle robot 100 then lifts the food product off the strip conveyor bybringing the lower supports 169 a-f, 167 a-f above the conveying surfaceand moves the food product towards destination packaging.

In one embodiment, the shuttle robot may move food product to acontainer 101 while the container is moving into the packing station110. The shuttle robot may move and track the position of a container131 and release a food product into the container while the container ismoving into the packing station and before it is stationary during thedwell period. Loading food products into the containers 131 during theadvance time period is a time efficient way to load the pockets.

After the containers 131 in the packing station have been loaded withfood product, the group of containers in the packing station is advanceddownstream to a sealing station 170. Containers 131 in the sealinglocation are sealed closed by the application of an upper web of film.The controller 180 synchronizes movement of the shuttle robot with themovement of the containers 131 and the conveyor 120 when needed.

The shuttle robot may fill the containers in any order, includingfilling the container closest to the main conveyor 120 first and fillingcontainers progressively toward the container located within the fillstation and furthest from the main conveyor. Alternatively, the shuttlerobot may fill the containers in reverse, wherein the first filled rowof containers is the row furthest upstream in the direction D (FIG. 1),and the shuttle robot advances to fill the second row, then advancesagain to fill the third row, etc. After the group of rows is filledduring the dwell period, the containers 131 advance and an empty newgroup of containers 131 is moved into the fill station 110.

In one embodiment, the gripper is configured to grip one food product orone stack of food products. In another embodiment, the shuttle robot hasa gripper that is a row gripper capable of gripping more than one foodproduct or an entire transverse row of food products and moving thosefood products to fill a transverse row of containers 131 in the fillstation. In another embodiment, the row gripper has multiplecorresponding pairs of gripping arms for gripping each food product of arow individually. This allows individual food products to be selectivelygripped. The row gripper is capable of moving less than an entiretransverse row of food products by selectively gripping the foodproducts. This may be desirable if one or more of the food products of afood product row is uncorrectable or otherwise unsatisfactory forpacking in one or more aspects, such as weight, form, or visualpresentation.

In another embodiment, the row gripper is capable of gripping alongitudinal row or column of two or more food products to move and filla longitudinal row of containers in the fill station. In anotherembodiment the row gripper has multiple corresponding pairs of grippingarms for gripping each food product of a longitudinal row individually.This allows individual food products to be selectively gripped. The rowgripper is capable of moving less than a longitudinal row of foodproducts by selectively gripping the food products. In anotherembodiment, the shuttle robot may comprise multiple shuttle robots forgripping and moving food products between the main conveyor and thepacking station.

From the foregoing, it will be observed that numerous variations andmodifications may be effected without departing from the spirit andscope of the invention. It is to be understood that no limitation withrespect to the specific apparatus illustrated herein is intended orshould be inferred. It is intended to cover by the appended claims allsuch modifications as fall within the scope of the claims.

The invention claimed is:
 1. A method of aligning food products on a conveyor, comprising the steps of: providing a food product on a conveyor; detecting a position of the food product with a sensor; and moving a mis-positioned food product from an original position on the conveyor to a destination position on the conveyor with a robot; wherein the step of detecting is defined in that the position is a vertical alignment position of food products in a food product stack; and wherein the step of moving includes positioning, with the robot, food products within the food product stack to bring the food product stack into a predefined vertical alignment.
 2. The method of claim 1, wherein the moving step comprises the steps of: lifting the food product from the original position on the conveyor; and placing the food product down on a destination position on the conveyor with the robot.
 3. The method of claim 1, after the step of detecting and before the step of moving, further comprising the steps of: determining whether a food product is robot-correctable food product with a controller; and wherein the step of moving is further defined in that only robot-correctable mis-positioned or mis-orientated food products are moved by the robot.
 4. A method of aligning food products on a conveyor, comprising the steps of: providing a food product on a conveyor; detecting a position of the food product with a sensor; and moving a mis-positioned food product from an original position on the conveyor to a destination position on the conveyor with a robot; after the step of detecting, comprising the following steps: sending a measured position value corresponding to the food product position detected by the sensor to a controller; and determining with the controller whether the food product is mis-positioned by comparing the measured position value one or more predefined position values.
 5. The method of claim 4, wherein the step of detecting is defined in that the position is an orientation of the food product; and wherein the step of moving includes rotating a misorientated food product from an original orientation on the conveyor to a destination orientation on the conveyor with the robot.
 6. The method of claim 4, wherein the step of detecting is defined in that the position is an orientation of the food product; and wherein the step of sending is defined in that the measured position value is a measured orientation value corresponding to the food product orientation; and wherein the step of determining is determining with the controller whether the food product is misorientated by comparing the measured orientation value with one or more predefined orientation values; and wherein the step of moving includes rotating a misorientated food product from an original orientation on the conveyor to a destination orientation on the conveyor with the robot.
 7. The method of claim 4, wherein the step of providing comprises providing a stream of food products on a moving conveyor; and wherein the step of detecting comprises detecting a position of each food product within a row width with the sensor; wherein sending comprises sending a position value corresponding to a position of each food product in the row width to a controller; and wherein the step of determining comprises determining a properly aligned position for each misaligned food product within the width row; and wherein the step of moving comprises moving each a misaligned food product from an original position on the conveyor to a destination position corresponding to the properly aligned position on the conveyor with a robot.
 8. The method of claim 4, wherein the moving step comprises the steps of: lifting the food product from the original position on the conveyor; and placing the food product down on a destination position on the conveyor with the robot.
 9. The method of claim 4, after the step of detecting and before the step of moving, further comprising the steps of: determining whether a food product is robot-correctable food product with a controller; and wherein the step of moving is further defined in that only robot-correctable mis-positioned or mis-orientated food products are moved by the robot.
 10. A method of aligning food products on a conveyor, comprising the steps of: providing a food product on a conveyor; detecting a position of the food product with a sensor; and moving a mis-positioned food product from an original position on the conveyor to a destination position on the conveyor with a robot; after the step of detecting, further comprising the steps of: sending to a controller the measured position value corresponding to the food product position as measured by the sensor; determining whether a food product is robot-correctable food product by determining whether the position value is within a predefined correctable position range; routing a non-robot-correctable food products to a correction station; and manually correcting the non-robot-correctable food products that are manually correctable.
 11. The method of claim 10, wherein the moving step comprises the steps of: lifting the food product from the original position on the conveyor; and placing the food product down on a destination position on the conveyor with the robot. 